Calculating machine



Nov. l2, 1946. r Y o. MEHAN 2,411,050

CALCULATING MACHINE Filed Dec. 25, 1940 10 Sheets-Sheet l NOV. '12, 1946. MEHAN CALCULATING MACHINE Filed Dec. 23, I940 10 Sheets-Sheet 2 INVENTOR. 7 mas-0. We.

- ATTORNE T. O. MEHAN CALCULATING MACHINE Nov. 12, 1946.

Filed Dec. 23, 1940 10 Sheets-Sheet 5 INVENTOR. f/xama Q/Ve/Zm 10 Sheets-Sheet 4 INVENTOR.

ATTORNEY.

Nov. 12, 1946. T, o, MEHAN CALCULATING MACHINE Filed Bed. 23, 1940 Nov. 12, 1946. T. o. MEHAN CALCULATING MACHINE Filed Dec. 23, 1940 10 Sheets-Sheet 5 IN VENTOR.

Nov. 12, 1946.

T.O.MEHAN CALCULATING MACHINE Filed Dec. 23, 1940 10 Sheets-Sheet 6 INVENTOR Nov. 12, 1946. HAN 2,411,050

CALCULATING MACHINE Filed Dec. 25, 1940 10 Sheets-Sheet 7 Nov. 12, 1946.

T. O. MEHAN CALCULATING MACHINE Filed Dec. 23, 1940 10 Sheets-Sheet 8 INVENTOR. BY f/iama (2276mm C5: iii

Nov. 12, 1946. T o. MEHAN 2,411,050

CALCULATING MACHINE Filed Dec. 25, 1940 10 sheets-sheet 9 Now-12,1946. T.'O.MEHAN ,4

- CALCULATING MACHINE FiledDec'. 25, 1940 10 Sheets-Sheet 1O Patented Nov. 12, 1946 CALCULATING MACHINE Thomas O. Mehan, Chicago, 111., assignor to Victor Adding Machine Company, Chicago, 111., a corporation of Illinois Application December 23, 1940, Serial No. 371,366

1 Claim.

This invention relates generally to improvements in calculating machines and more particularly to adding and subtracting mechanisms for use in such machines.

The general object of the invention is to provide adding and subtracting mechanisms de-- signed particularly for compact arrangement in portable calculating machines.

Other objects and advantages of the machine will be mentioned hereinafter or will become apparent from a perusal of the specification and drawings, wherein a preferred form of the invention has been illustrated and described.

Fig. 1 is a front elevation of a partial assembly of the adding and subtracting mechanisms hereinafter described.

Fig. 2 is a vertical sectional view substantially on the plane of the broken line 2-2 of Fig. 1.

Fig. 3 is a vertical sectional view substantially on the plane of the line 22 of Fig. 1, looking in a direction opposite to that on which Fig. 2 is taken.

Fig. 4 is a side elevation taken at the left side of Fig. 1.

Fig. 5 is a side elevation taken from the right side of Fig. 1.

Fig. 6 is a side elevation of a few elements normally mounted on the main shaft in the foreground of Fig. 5.

Fig. 7 is a front elevation of the main shaft assembly.

Fig. 8 is a right elevation of the same assembly.

Fig. 9 is a partial side elevation of the left side of the machine, emphasizing the subtractor key and associated mechanisms.

Fig. 10 is an assembly view in elevation taken from the right side of the machine, emphasizing the total key and associated mechanism controlled thereby.

Fig. 11 is a plan view of the accumulator swinging frame assembly.

Fig. 12 is a side elevation of the same assembly.

Fig. 13 is a side elevation of the shiftable accumulator assembly itself.

Fig. 14 is a front elevation of the Zero eliminator assembly.

Fig. 15 is a side elevation of the same assembly.

Inasmuch as this application is not concerned with the keyboard unit, the details of that complete unit and the frame for supporting it are not shown in this application. The keyboard unit which is preferably used with the present invention is that which is shown. in my copending application, Serial No. 282,787, filed July 4, 1939. Likewise, a ribbon mechanism suitable for use with this machine is also shown in the same co-pending application. As this invention is particularly concerned with that part of the machine which performs the addition and subtraction, subject to the control of the keyboard unit, only so much of the machine as is necessary for the understanding of the present invention is disclosed herein.

Frame The frame employed with the present invention comprises a base plate 1 on which are mounted a pair of outside vertical frame plates 2 and 3 and a pair of intermediate vertical frame plates 4 and 53. Preferably, a plurality of projections such as G on the vertical plates will extend through corresponding slots in the base plate and will be swaged over to lock the frame plates together.

The keyboard unit fully described in the above mentioned application, is shown in part in Fig. 2 in order that its operative relation to the present invention may be clearly understood.

The outside vertical frame plates are employed not only in supporting the keyboard unit, but also in furnishing the pivotal support for the total key and for the repeat and subtracting keys, and in addition thereto, the support for the ribbon mechanism, as will be better understood by reference to the above mentioned co-pending application.

The full stroke mechanism preferably employed in connection with the present invention is that Which is shown in my aforesaid application, Serial No. 282,787.

Printing mechanism Controlled in their rearward travel by the key stems such as 'i are the stop slides 8, one for each bank of numeral keys. A comb 9, mounted on the cross channel member i i spaces and guides the set of stop slides. Each slide is normally urged rearwardly by a coil spring l2 connected to the comb at any suitable point on the slide.

Laterally extending projections such as 13, suitably spaced, are provided on each stop slide to engage any key stem which may be depressed whereby the corresponding number may be printed by the machine.

Rigidly connected with each stop slide, and offset to an appropriate extent for each bank, as shown in my aforesaid application, is a bracket 14 pivotally connected with a rack bar such as 15. The rack bars are spaced and guided by combs l6 and i7 rigidly supported in any suitable manner by the frame, and are further guided by the rods 18 and I9 which extend through the 3 slots 2| and 22, and are urged rearwardly by springs i2.

As shown in Fig. 2, each rack bar is provided with a set of lower rack teeth 23 and an upper set 25. The upper set engages teeth 2%: provided on the type carrying wheel 25 which is rotatably supported on a shaft 21 carried between the intermediate frames of the machine. Each type carrying wheel is provided with a set of numeral types for printing the digits zero to nine, and preferably each set of type will be a single unit 28 secured by welding, riveting, or otherwise to the wheel. Also, each type wheel is provided with a set of teeth such as 29 which may be engaged by a bar 3! on the rectifier bail 32 for holding the type characters in proper alignment during a printing operation. lhe operation of the rectifier bail is the same as described in my aforesaid co-pending application.

It will be understood that it is preferred to use a swingable platen roll for pressing the paper against the type characters. This platen be mounted oscillatably upon the shaft 33 and rocked forwardly and downwardly to bear against the type characters in the plane of the comb which is located at the printing plane.

As in the case of the machine described in my prior application, the rack bars on any printing operation are enabled to move rearwardly in accordance with the setting of the numeral keys and their coaction with the lateral projections on the stop slides a.

Cooperating with the lower teeth on each rack bar is an adding sector designated by its teeth 35, and which is mounted rotatably on a shaft 36. Each adding sector is mounted coaxially with and connected through a lost motion mechanism to an associated accumulator sector 3'5, having teeth 33.

Fixed on the same bushing 39 to rotate about shaft 36 integrally with each adding sector is a member ii having an offset ear 42 extending through a slot d3 provided in the associated accumulator sector 37 and aligned so that it may strike the straight edge margin of that slot. Each member iii also has an car 44 to'which is connected a. spring extending through a slot in the associated accumulator sector, the other end of the spring being anchored at M on the ac- V cumulator sector. Thus the initial rearward travel of the rack bar will first rotate the adding sector 35 andv member 5! until the ear 42 strikes the end of the slot 43, after which the sector 35 and sector ill will rotate together.

Accumulator mechanism 7 In an ordinary adding operation after the desired numeral keys in the keyboard have been set, the main operating shaft 38 is rotated by the handle or by any other suitable power means, whereupon the stop slides in the associated rack bars will begin to move rearwardly, except whenever held stationary by the zero stops in banks where no numeral'keys have been set. Each asbe temporarily locked in position by the rectifier bail 32. As soon as the'return stroke begins, the

accumulator mechanism is brought into oper-' ative relation with the accumulator sector 31 in a manner which will now be described.

The accumulator gears 5i and and the zero eliminator gears 53 are mounted in a sliding carriage formed of a pair of side plates 5% and 55, which support between them the shafts 55, El, and 58 on which the gears are individually mounted. Also carried by the side plates f l and 55. are the accumulator locking plates as and iii, projections on these plates extending into suitable apertures in the side plates forming the hinges on which these plates may rotate to looking or unlocking position. Each locking plate is provided with a spring such as 52 and 5:3, as shown in Fig. 3, for holding the plate engaged with the teeth of the accumulator gears when ever the accumulator carriage is in its lower inoperative position. These springs are connected with the plates and anchored on the posts 64 and 55 which are likewise carried on the carriage side plates.

The accumulator carriage is adapted to occupy a rearward position during adding and totaltaking operations and to be slid forwardly for subtracting operations. Accordingly, it is reciprocably mounted in a swinging accumulator frame comprising a pair of arms 65 and El secured to a shaft 68 rotatably supported by the lowermost extensions of the intermediate frame plates d and 5. The forward end of each of these arms has an upward extension whose function will later be described. The rearward portions of the swinging frame arms are provided with the longitudinal slots $5 and ii providing slideways for bosses '52 and i3 provided on the accumulator carriage plates at and 55. Each of the carriage plates is also provided with a laterally projecting post such as i l and it by means of which the carriage is reciprocated in the subtracting operation.

For raising and lowering the accumulator swinging frame, a link 76 is pivotally connected to a post ll provided on an upwardly extending portion of the accumulator swinging frame arm 6?, and the upper end of the link is pivotally connected with a post '58 carried by arm '59 fixed on the rock shaft ti carried between the intermediate frame plates, this latter arm being connected by the pin 82 to the accumulator selector 83, this pin being rigidly secured to the arm '59 and extending through a slot 8 in the intermediate frame plate 5.

As shown in Fig. 13 and Fig. 2, the side plates of the accumulator carriage are provided with looking slots it], either of which will engage with thepin 86 on the adjoining stationary intermediate frame plate of the machine when the accumulator carriage is raised at adding position or subtracting position.

Accumulator carriage shiftin In'brief, the three sets of accumulator gears are utilized as follows: Those on the shaft 56 are lifted into engagement with the accumulator sector 31 at the beginning of the return stroke in an adding operation, and lowered out of engagement at the end of the return stroke of the operating handle. In a total-taking operation, the accumulator gears on the shaft 56 arelifted into engagement with the accumulator sector at the beginning of the forward stroke of the operating handle and lowered out of engagement at the beginning of the return stroke. total-taking operation, the same accumulator In a sub-' gears are lifted into engagement with the accumulator sector at the beginning of the forward stroke and held in engagement until the end of the return stroke, whereupon they are lowered.

For a subtracting operation, the accumulator carriage is reciprocated forwardly during the forward stroke of the handle and thereafter the accumulator gears on the shaft 51 are lifted into engagement with the accumulator sector 31 at the beginning of the return stroke and dropped out of engagement at the conclusion of the return stroke. If the next operation is an adding operation, the accumulator carriage will be automatically returned to its rearward position during the forward stroke of the handle, but if the next operation should be a total or a subtotal-taking operation, the rotation of the total key to either of those two positions will of itself instantly return the accumulator carriage to its rearward position. However, if two successive subtraction operations are performed, the carriage will remain in the forward position for the second operation if the subtraction key has again been actuated for that operation.

Accumulator selector mechanism In this machine which performs both additions and subtractions, I preferably employ the same accumulator selector mechanism which I have shown in my co-pending application, Serial No. 282,787, which has been referred to above. So far as adding and total-taking operations are concerned, this mechanism is actuated by an operating plate 85 fixed on the main operating shaft 48 and carrying an accumulator control pawl 86 pivotally carried by the plate on a pin 81. The operating plate 85 and the control pawl carried thereby are shown in Fig. 8, while the position of the operating plate when at rest is shown in dotted lines in Fig. 5. When the machine is at rest the tongue 88 on the control pawl rests against the left side of the post 89 fixed on the accumulator selector plate 9|. When the operating shaft is rotated on the forward stroke of the handle, the righthand notch 92 in the accumulator selector pawl passes underneath the post 89 without pushing against the same, and as it moves beyond that position, the spring 93 attached to the control pawl tends to rotate the pawl in the direction shown in the assembly view of Fig. 8. When the forward stroke has been completed, the left side of the tongue 88 on the pawl is then resting underneath the post 94 at the forward end of the accumulator selector plate 9I. When the return stroke begins, the lefthand notch 95 in the control pawl will then engage the post 84 and lift it, thereby rocking the accumulator selector plate about its pivot 95 in a clockwise direction as viewed in Fig. 5. At this time, inasmuch as the notch 91 in the left sideof the accumulator selector is engaged with a post 98 carried by the accumulator selector plate, the rotation of the latter plate will lift the accumulator selector 83, whereupon the accumulator swinging frame will be raised through thecooperation of the post 82 which connects selector 83 with arm I9 (Fig. 3) and the link I6 connected at TI to the swinging frame arm 6?. This brings the accumulators on shaft 56 into engagement with the adding sector teeth 38. Thereby, when the return stroke is taking place, the various adding sectors which have been rotated from zero position during the forward stroke, will rotate their associated accumulator gears 5| an equal amount as the adding sectors return to zero.

In order to make certain that the accumulator swinging frame i positively held in its lower position during the forward stroke and is held in its upper position positively during th return stroke, there is provided a cam 99 shown in dotted lines in Fig. 5 which will be rotated during the forward stroke underneath a cam follower I III and remain in engagement with said cam follower almost to the end of the forward stroke. The cam follower is carried on one arm I02 of a bell crank, whose other arm I03 is provided with a pair of notches as shown to engage a post I04 on the upwardly extending portion of the rear end of the arm 19 a short distance above the link pivot I8. crank, consisting of the arms IOI and I03, is held resiliently against the post I84 by means of the Spring I85. Whenever the accumulator Swinging frame has been lifted by means of the accumulator selector 83 as described above in connection with an adding operation, or otherwise, the upper notch on the bell crank will hold the accumulators in the upper engaged position. When the return stroke is just being completed, the lower rear end of the cam plate 99 is positioned so that it strikes against the post 82 fixed on the arm I9, and as it moves further to the completion of the return stroke, it forces the accumulator frame down to its inoperative position, the yielding mounting of the locking arm I83 permitting this to occur. This arm is pivoted on the shaft 27 so that it may rock the slight amount necessary.

The foregoing description of the operation of the accumulator selector mechanism applies to an adding operation. So far as the lifting of the accumulator frame is concerned, the same description will apply to a subtracting operation.

The functioning of this selector mechanism in a total key operation will now be described in connection with the description of the total key mechanism.

Total key operation he locking mechanism employed for locking the total key either in neutral, in total, or in subtotal position is the same as that shown in my co-pending application Serial No. 282,787, above mentioned, and therefore will not be described herein. Also, for the same reason, the mechanism by which the total key, when rotated either to total or sub-total position, clears the keyboard, likewise will not be described here.

While it will be recognized that in principle and in construction there is considerable identity between the total key mechanism shown in my application 282,787 and that shown herein, a description of the remainder of the mechanism will be required herein because of its relation to the different accumulator mechanism which this specification discloses.

-..e total key III, shown in neutral position "gs. 5 and 10, from which it is rotatable forwardly to total position or rearwardly to sub-total position, is attached to a stem H2 secured to a bail H3 pivoted at lid. The lower end of one leg of the bail H3 carries a post H5 extending through a slot I I6 of a bell crank arm I I! pivoted at I i 3. When the total key is rotated to sub-total position the post 5 i5 acting on slot 5 it will rotate the bell crank counter-clockwise, as viewed in Fig. 5, to place the lowermost edge of the bell crank arm I I8 in position to be engaged by a short The accumulator locking bellpost I2I on the side of the accumulator selector control pawl 86 as the forward stroke is being completed, where-by on the return stroke the left notch 55 of the pawl will be held down out of engagement with post 9 3 of the accumulator selector .plate 85. If the notch 95 were permitted to engage and lift the post 3 5 at this time on the return stroke, the accumulator plate 1% would be rocked clockwise, causing the selector 3-? to be lowered, which would thereby cause the accumulators to drop down at the beginning of the return stroke, as is done in a total taking operation.

Describing further the sub-total operation, the total rotated rearwardly either before or after the numeral keys have been set in the keyboard, whereupon the rotation of the key to subtotal position will rock the total control lever, generally indicated as 522 in Figs. 5 and about the axis I23. The total control lever proper, designated I22, has its upper end formed as the left leg of a bail IM pivoted at I23, the right and shorter leg of the bail having a rearward extensio'n I25 carrying a post 52% positioned to slide in a r shaped slot Illl formed in one leg of the total key bail I this leg being designated as 5'23, being riveted or otherwise secured directly to the key stem I l2 and pivoting about the shaft us. The action of the slot I27 on the post I26, whether the rotation be to sub-total or total position, has the effect of rotating the total control lever I22 in a counter-clockwise direction as viewed in Fig. 5 and Fig. 10. At the same time, the keyboard will be cleared and locked against further operation, but the mechanism for that purpose is the same as is described in my copending application 282,787.

Referring further to the total control lever, the forward leg I29 of this lever is connected by link I3I to an arm I32 secured on a rock shaft I33 which serves the purpose of releasing the zero stop 53 3 (see Fig. 2) which, except in a totalizing operation, engages the ear I39 on the rack bar to the extreme left in the bank of rack bars, this zero stop being pivoted at I35 and held normally engaged by a spring this rack bar, not associated with any stop slide or key bank, will be drawn rearwardly by its spring ifiil to the extent determined by the sum, if any, accumulated in its associated accumulator by tens transfers from the highest key bank on its right, and thus its type wheel may print such sum.

If the accumulator carriage is in subtraction position, the rotation of the total control lever will cause finger 37 at the bottom thereof to push rearwardly on the post I 3i" fixed on the pivoted arm 538. This arm pivots on shaft 35, and the slot in its lower end, engaging the post l5 on the accumulator carriage, will thereby slide the carriage rearwardly to total position. I

A further and'primary function of the shifting of the control lever is to cause the link I39, pivotally connecting post 39 on the control lever and post MI on the accumulator selector 88, to

cause the selector to rotate rearwardly whereby the notch I2 on the selector will engage the post I43 on the accumulator selector plate SI and rotate'the latter a small amount in a clockwise direction. as Fig. 5 is viewed. Thereafter, when thev forward stroke begins, the forward rotation the operating plate 85, which carries the selector pawl 86, will cause the right-hand notch of the pawl to engage the post 39 and lift upon it to lift the selector 83 and thereby post 82, the

arm I9, link 16, and the accumulator swinging When thus released frame (Fig. 3) immediately at the beginning of the forward stroke. This brings the accumulators on shaft 56 into engagement with their associated adding sectors 31, whereby the rotation of each accumulator toward its zero position by the action of the spring-propelled rack bars during the forward stroke will allow a corresponding rotation of the type wheels and cause the printing type wheels to print the amount therein registered at the end of the forward stroke.

As just explained above, the rotation of the total key to sub-total position has also swung the lever H9 rearwardly, so that it will prevent the accumulator lock arm I83 from releasing the accumulators at the beginning of the return s roke. Accordingly, the accumulators remain in engagement with the adding sectors to the end of the return stroke and thereby re-accumulate the sums which they previously contained.

The total key is always returned to neutral position by a spring I44 connected directly to the total key, and the accumulators will be forced out of engagement with the adding sectors just at the end of the return stroke by the bumping of the lower end of the cam 99 against the post 82, as explained above in connection with an ordinary adding operation.

The function of the slot I45 provided in the total control lever will be described later in the description of the zero eliminators,

For a total-taking operation, the total key is rotated forwardly. The movement of the V- shaped slot I2! acting on post I25 will rotate the bail I2 3, causing the total control lever I22 to rotate counter-clockwise just as in the subtotal operation. However, the post I IE will move through the slot '6 in the bell crank arm 'I I7 without causing the arm I I9 to rotate, as it does in a sub-total operation. The rotation of the total control lever causes the link I39 to throw the accumulator selector '83 to the right, as viewed in Fig. 5, engaging the notch I42 with the post I43. Therefore, at the beginning of the forward stroke, the accumulators on the shaft '55 will engage the adding sectors. During the forward stroke each of the accumulators will be rotated back to zero by the adding sectors, and their total will be printed at the end of the forward stroke when the rockable platen is brought into engagement with the type wheels.

In View of the fact that the arm IIB has not been rotated by the total key, the accumulator control pawl will strike the post 94 at the beginning of the return stroke to thereby raise it and rotate the accumulator selector plate 9| clockwise, thereby lowering and releasing the accumulators. Thus, the accumulators, having been restored to zero on the forward stroke, will not be disturbed during the return stroke.

The arm I46 shown in Fig. 10 having a curved slot I I! and a central notch I48, is provided for the purpose of locking the total key against operation while the subtraction key is in subtracting position. Accordingly, this arm I46 is fixed on a shaft I49 and is positively rotated downwardly by the operation of the subtraction key to bring the notch I43 into engagement with a post I5I extending from the side of the key stem plate H2.

Subtraction and repeat key The key I52 fixed on the key's'tem I53 serves as a'repeat key when rocked forwardly, as in the aforesaid application Serial No. 282,787, and when rocked re'arwardly it sets up'the mechanism for a subtraction operation. The key is .pivoted at I54 and is provided with the notched projection I55 shown in Fig. 9 which cooperates with the follower I59 on the arm I51 to hold the key in neutral, forward, or rearward position, the arm being pivoted at I59 and being urged toward the key by the spring I59 anchored at IfiI. Whenever the key is rocked to subtract position a pin I62 travelling in slot I63 in arm I64, fixed on shaft I49, will lock the total key in neutral, as previously explained.

The key I52 has a depending leg or finger I95 whose function is to prevent the release of keys which have been set in the keyboard when it is desired to repeat the addition of a sum set up therein. A plate I66, shown wholly in dotted lines in Fig. 9, and pivoted at M51, is secured at its forward upper end I98 to a bar 599 which extends across the machine in position to strike all of the key lock slides thereby releasing the set key stems, if the repeat key is not in repeat position. A plate I1I, mounted on the main operating shaft 48 to rotate in unison therewith, carries a post I12 which will operate the keyboard clearing bar on the return stroke, normally. A dog I 13 pivotally carried at I 14 on the rear extremity of plate I96 is normally held by a spring I15 sothat its upper end rests against a laterally projecting ear I16 on the plate I69. When the plate I1I' rotates forwardly with shaft 48 the post I12 strikes but passes under the lower end of the spring held dog I13, but on the return stroke the dog is struck again and since it bears against the ear I16 the dog and plate I96 are rotated about the pivot I61 to release the keyboard.

However, if the repeat key had been rotated forwardly, the finger IE at its lower end would have engaged the post I11 on the side of dog I13 and rotated the latter so far counter-clockwise (Fig. 9) that the dog would entirely clear the post I 12, thus avoiding any release of the keyboard.

A plate I18 is secured rigidly to the key stem I53 in spaced relation by posts I19 and IBI. A curved slot I*82 in plate I18 is provided so that the plate may rotate relatively to a post I93 mounted on the adjoining vertical frame member and pivotally carrying a dog I84 whose upper end will be engaged by the post I19 when the key is rotated to subtraction position, thereby rotating the lower end of the dog clockwise (Fig. 9). As the dog is thus rotated, its lower end will strike the post I11 on the side of the dog I13 and will rotate the latter out of the path of the post I12 on the plate I1 I. -Hence, if the operator desires to repeat a subtraction and will hold the subtraction key so that it will not be released at the end of the return stroke, the keyboard will not be cleared. If the subtraction key were allowed to be returned automatically to neutral position during the return stroke, the keyboard would be cleared.

The key I52, if in neutral position at the time the forward stroke begins, will be locked against rotation to the subtraction position, or if in subtraction position at the beginning of the forward stroke, will be locked against rotation therefrom by means of a locking arm I85 pivoted at I89 which cooperates with the projection I31 on the bottom of the plate I18. The spring I98, anchored on a post I89 supported by the adjoining side frame plate, normally holds this locking arm in lowered inoperative position, but as the main shaft 48 rotates forwardly, the cam plate I9I will strike a follower I92 carried on the side of the locking arm to thereby raise the locking arm into engagement with projection I81 during the completion of the forward stroke and until near the end of the return stroke, as the follower rides over the periphery of the cam. A post I93 extending through the slot I94 in the locking arm and having an enlarged head bearing against the face of the locking arm is provided to guide the locking arm in its oscillatory movement.

The key I52, unless held in subtraction position by the operator, is automatically returned to neutral during the return stroke in the following manner: The arm I51 whose follower I55 engages the notched edge of the key stem to hold it releasasbly in either of its three positions has connected with it at the pivot I95 a link I99, whose other end is connected to the pivot I91 of a dog I99 pivotally carried on a rocking plate I99 rockably mounted on the fixed post 91. A spring 2m, connected with the dog as shown and anchored on the post 292, likewise carried on the plate I99, normally urges the dog in the direction indicated in Fig. 9. Hence, during a forward stroke, the post I12 will rotate the dog I98 against the action of its spring and'pass thereunder without pushing on the link I96. But on the return stroke of the plate Ill and post I12, the latter will strike the lower end of the dog I98 and lift it, since its upper end bears against the sleeve 299 surrounding the post I61. This lifting of the dog pushes on the link I95 and releases the follower I55, whereupon the key stem is restored to normal by the action of the spring I15 causing the pin I11 to bear against the lower end of the dog 94, whose upper end pushin against post I19 will restore the key to normal or neutral position.

At the same time, as the key I52 rotates to neutral position, the lower end of dog I13 will drop down into its normal position in time to be engaged by the post I12 on cam I 'II and causing the release of the keyboard as the plate I98 is rotated clockwise.

On the forward stroke, cam I9I, which is rotatably mounted on shaft 48, is pulled forwardly by a latch I89 engaged with an ear I89 on a plate I99 which is fixed on the shaft. The latch is pivoted at 991 on a post carried by cam I9I and extending through slot I99 in the fixed plate 5 99. The spring 299 is connected as shown with the latch and anchored on the fixed plate so that when the parts are at rest, the cam rests against the stationary post 299'. During the forward stroke, the rear end of the latch I89 will strike the pin I92 on the key locking arm I85, thereby releasing the latch, whereupon the spring 299 will draw the cam I9I rearwardly to the extent permitted by the travel of the pivot post I91 in the slot I99. However, the key locking arm will still be held up by the cam I9I during the remainder of the forward stroke.

On the return stroke, in View of the fact that cam I9I has been withdrawn rearwardly by spring 299, the cam follower I92 on the key lockin arm will ride off the edge of the cam sooner than if the cam had not been retracted. This release of the key locking arm is thus timed in such a manner that as the locking arm drops down, the subtraction key may be restored to normal during the remainder of the return stroke, as just above described.

A further result of the rotation of the key to subtraction position is noted in the action of a post 294, which is fixed on the plate I18, as it strikes the upper end of the vertical lever 295 pivoted on the side frame at I93. The clockwise rotation of this lever causes the pin 206, carried in its lowered end and engaging the U shaped slot 26?, to rotate the bail arm 208 pivoted at 289 in a counter-clockwise direction (Fig. 9). The other arm 2H of the bail has a bifurcated or slotted end which engages a pin 2l2 on a bell crank generally indicated as 2l3 pivoted at 2 l4, and whose other arm 2l5 is likewise bifurcated to engage the pin 2! 3 in the lower end of an arm 2i? fixed on a rock shaft 2l8 (Figs. 4 and 9). As shown in Fig. 3, the rock shaft 2H3 being thus rotated in a counter-clockwise direction (Fig. 4) will cause another arm 2i9 fixed on the same rock shaft to press downwardly in the slot 2!! in the plate 222 by means of its post 229.

This movement of the arm H9 in a counterclockwise direction pulls downwardly on plate 222, which has a central slot surrounding the type wheel shaft 27, and the slot 223 in this plate will acton pin 224 to rotate the signal type wheel 225 (Fig. 3) counter-clockwise a suflicient distance to bring the minus sign type to the printing position, to indicate that a sum has been subtracted in the operation. At this point it may be stated that the rock shaft 2"; does not move when the total key is operated to sub-total or total position, and although the signal type wheel is rotated, the pin 220 in the slot 22| will not interfere with the movement of the signal type wheel and the plate 222 which moves along with it.

It has been explained above how the operation of the total key will positively return the accumulator carriage to normal total-taking (or adding) position if the carriage should happen to be in subtraction position when a total is next desired, that is the finger I31 (Figs. 6 and 10) will thrust against post I31.

It will now be explained how the carriage is shifted to subtraction position. When key I52 is rotated rearwardly, the post 204 rotating integrally with it rocks arm 205 and the bail having arms 208 .and 2H, as previously explained. As the bail rotates counter-clockwise (Figs. 9 nd 4) about its axis 209, the link 226 pivotally connected at 221 to the bail will be pulled downwardly, guided by its slot 228 on the pin 223. The laterally extending post 23! carried by the link will push down the rear end 232 of the arm generally indicated as 233 pivotally carried at 234 on the accumulator carriage shifter arm 235, which itself is pivotally supported at 236. The extent of the movement of the arm 233 is such as to rotate it high enough that the upstanding projection 23! on the arm may be engaged by the post 233 as the latter is rotated rearwardly during the forward stroke of the machine. Ihe post 238 is fixed on one end of a lever 239 pivoted on the frame at 24i and having an open ended slot 242 which is constantly engaged by a post 243 fixed on the side of a cam plate 244 mounted on shaft 48 and rotating therewith. As shown in Fig. 4 the shifter arm 235 has a slot 245 in its lowered end and which is constantly engaged with a pin 14 fixed on the left side of the accumulator carriage. Consequently, When the key I52 has been rotated to subtraction position and the arm 233 rocked upwardly and the forward stroke thereafter initiated, post 238 will push against the shoulder 23'! to thereby push arm 233 bodily rearwardly, rocking the shifter arm 235 about its pivot 236, thus throwing the accumulator carriage to the forward subtraction position. If the key is not manually held in subtraction position, it will be automatically released, as heretofore ex- T2 plained, on the return stroke, which will leave the arm 233 and shifter arm 235 in the position shown in dotted lines in Fig. 4. When the subtraction key is restored to neutral the link 226 and the bail to which it is connected will be restored to the position shown in Fig. 4.

If the key H52 is still held in subtraction position or is restored thereto while the carriage is still in subtraction position, the downward movement of the link 226 will rock the arm 233 counter-clockwise so that the hook 226 will be raised above the path oftravel of post 243 during the forward stroke. However, if the key is in neutral position, the post 243 will engage this hook during the forward stroke, pull the link 233 forwardly, rocking the shifter arm 225 clockwise, and thereby restore the carriage to adding or total position before the forward stroke is completed. Thus the accumulators will be automatically restored to position to perform addition if an adding operation follows the subtraction operation. This will leave the parts in the position shown by full lines in Fig. 4. A spring 24'! bears against post 248, is wound around the pivot 234 and hooks over the link 233 to urge the latter in a clockwise direction. Thus, the rear end of the arm will bear either against the post 23I, or when the carriage is in forward position and the key 52 in neutral position, the post 248 will limit the clockwise rotation of the link. The shifter arm is releasably locked in either position by the arm 249 pivoted at 2A9 bearing against pin 250 on the shifter arm under the downward pull of spring 25L Accumulators Whether the accumulator carriage is in its rearward adding position or in its forward subtraction position, the accumulators when dropped down always are held locked by the locking plates 59 and BI, best shown in Fig. 2. Whenever the accumulators are raised for engagement with the accumulator sector teeth 38, these locking plates will become disengaged from the accumulators when the ears 252 (Fig. 5) strike against the upper margin of the slot 253 in the right-hand intermediate vertical frame plate 5. The pivotal support for the locking plates is shown in Fig. 5 at 254.

In an adding operation, each accumulator on the shaft 56, being engaged with the accumulator sector teeth 38, will be rotated to an extent determined by the rearward travel of the associated rack bar, which in turn moves to the extent determined by the keys in its ownbank.

In a total-taking operation the rack bars are released for rearward movement by their springs l2, and the extent to which they may travel will be determined by the associated carrier pawl acting on the carrier cam which is integral with each accumulator wheel. Referring to Figs. 2, 11, and 13, it will be observed that each of the accumulator gears 51 on the shaft 56 carries integrally with it a cam 255 which has a projection 256 for cooperation with the carrier pawl. The carrier pawl itself is shown in Fig. 2 as 251, pivoted for oscillation about a shaft 258, and having a cam follower projection 259 which rides on the carrier cam whenever the accumulators lil are raised. The spring 25 insures this contact of the pawl and cam. 'Whenthe accumulator is being rotated toward zero during .a, total-taking operation, 'it may continue to rotate :until the *nose 259 of the carrier pawl strikesthe radially extending face of the carrier cam projection 256.

This is at the zero position of the accumulator. 1

Of course, it will be understood that in a subtotal operation after each accumulator has been rotated to zero and stopped by the above described cooperation between its carrier pawl and cam projection 256, the return stroke of the machine, with the accumulators still engaged with the accumulator sectors, will restore each accumulator to the position formerly occupied by it before the sub-total was taken.

The tens transfer is accomplished as follows: During an adding operation the accumulators on the shaft 52 are raised and meshed with the accumulator sector teeth 38 at the beginning of the return stroke. The rack bars having moved rearwardly in accordance with the key setting in their associated banks are restored to their normal forward position by means of the rack restore bail 262. This bail is carried on a pair of arms pivoted on the shaft 27, one of the arms 263 being disposed outside of the right-hand intermediate frame plate, and the other 264 being mounted outside the left-hand intermediate frame plate. The latter arm is provided with a gear sector 265 meshing with another gear sector 266 mounted on the cross shaft 261 'and connected in any suitable manner to rotate integrally with the rack restoring cam 268. This mechanism, described in my aforesaid application, is operated by the post 26% mounted on the side of the cam plate HI, the post entering the cam surfaces formed by the bifurcated legs of the rack restore cam and positively restoring the various type wheels and their associated racks to normal position as the bail rod 262 engages the bottom of the curved slot 2' in each type sector wheel during the return stroke.

As the racks are propelled forwardly to their normal position by the bail rod 262, th lower set of rack teeth 23 acting on the accumulator sector teeth 35 will rotate each accumulator sector towards its normal position, which is shown in Fig. 2. But if any accumulator gear 5| shall have during the return stroke of the adding operation rotated past its zero position, the sloping side of the carrier cam projection 256 will have lifted th associated carrier pawl and enabling the latter to become locked in raised position. The mechanism for locking is shown in Fig. 2 consisting of a locking pawl 272 rotatably mounted on shaft 233 and held under tension by spring 26 I. Should the carrier pawl be rotated to raised position, the shoulder 273 on the carrier pawl willbe rotated down far enough to permit the lowermost edge 2M of the locking dog to override the end of the pawl and thus hold the carrier pawl in raised position even after the projection on the carrier cam has passed. Referring to Fig. 2, it will be observed that therefore as the accumulator sectors 31 are being rotated counterclockwise to their normal positions, the laterally projecting ear 215 on any accumulator sector plate will be able to enter the notch 21 6 on the carrier pawl to the right of the individual accumulator sector if such pawl to the right has been raised. Thus, after the rack and adding sector have rotated the gear to the extent determined by the key setting in its own associated bank, the spring &5 connecting the adding sector and accumulator sector will rotate the gear one tooth further if the carrier pawl to the right thereof is held locked in raised position. Thus the tens transfer is accomplished.

As the accumulator carriage is dropped down at the end of the return stroke, the cross bar 270 which extends between the accumulator frame arms 66 and 67 will bump against the lower portions of the carrier pawl locking dogs 212 (Fig. 2) and rotate each of them, if previously displaced back to the position shown in Fig. 2. However, if any of the carrier pawls have been lifted, they will still remain raised because of the: engagement of the notches 276 with the ears 2l5.-

The carrier pawls are restored to their normal. position as follows: Referring to Figs. 2, 3, 6, and. 8 it will be observed that the plate fixed on the main operating shaft carries a post 271 which. at the normal position lies in a notch 218 in the carrier restore pawl 279. This pawl is pivotally' carried at 26| on the plate 282 which in turn. is pivoted on the rock shaft 2E8. The spring 283; connected to the pawl and plate serves to hold the pawl against post .217. The plat 282 whose rearward extremity normally rests against the. post H8 constitutes one leg of a bail having a cross bar 264 held downwardly by the spring 285,. and whose other leg is the arm 286 pivotally connected at 281 to a link 238 pivotally conmeeting it at 28% to an ear 29| depending from a carrier restore plate 292 fixed on the rock shaft (Fig. 3). When the plate 85 (Fig. 6) begins to rotate at the beginning of the forward stroke, the post 211 will push against the pivot of the pawl 219 and rock the bail 282-286 in a clockwise direction as seen in Fig. 2 or in a counter clockwise direction as seen in Fig. 3, causing the carrier restore comb 292 to swing downwardly toward the uppermost teeth 38 of the adjoining accumulator sectors (Fig. 2). If any of these accumulator sectors have rotated one tooth beyond the position shown in Fig. 2, that is whereby their ears 2'55 have entered a carrier pawl notch 276 in tens transfer position, the carrier restoring comb 292 will push them all back to normal, and the associated springs 26l will restor th carrier pawls to the position shown in Fig. 2. Hence, this machine, as is equally true of the machine described in the above mentioned patent application, does not require an idle stroke between an adding operation and a total-taking operation.

When a subtraction is being performed, the accumulator gears 52 on the shaft 5! are raised into engagement with the accumulator sectorteeth 38, and the carrier pawls cooperate with the carrier cam projections 256 in the samemanner as they do in the adding operation just described. If during subtraction, any accumulator on shaft 57 be rotated past its zero position, the carrier pawl which will be thereby raised and; locked will enable the accumulator to the left thereof to rotate one tooth further, thereby subtracting ten from the adding accumulator in gear therewith.

The third set of gears 53 on the shaft 56 are provided for the purpose of operating the zero eliminators which will now be described.

Zero eliminator To eliminate the printing of zeros to the left of the first figure which should be printed in any total printed by the machine, that is where the total is les than the full capacity of the machine, zero eliminators as shown in Figs. 14 and 15 and Fig. 2 are provided to cooperate with the third set of accumulator gears on the shaft 58. Each of these accumulators is provided with a cam 30! having a notch 362 which will occupy the position shown in Fig. 2 if the highest figure in the total does not extend into the bank with which any such accumulator is associated. When the total key i operated either to sub-total or total position, the, rocking of the total control, lever, en rally indicated. as. 5 in Fi ,.W l aus the. slot, lddto, push rearwardly against a pin; 383 mounted on the sidcqf a lever 353% (Fi 5) pivoted on post 305 pivotally connected with a post 3&5, extending through a slot 301 in the intermediate sideframe plate. The post 3 35 constitutes the pivotal,connectionbetween the lever 3'38, (Fig. 3), f xed on the rock shaft sea and the right hand side plate 311 of the zero eliminator frame. Thi plate has a slot 3I2 surrounding a cross rod 3 i BwhiCh passes through allot the zero eliminators andwhich is fixed on the side frame members 3}! and 3H! of the zero eliminator assembly, Accordingly, when the rotation of the total control-lever pushes the post 383 rearwardly, causing the post Stifto be pulled downwar l the assembly frame-members 3H and 3M carry the rod 313 downwardly and thereby carry along with them each of the individual; eliminators such as 315, 3J5, 3H, andfild, illustrated in Fig. 1%. That is, the individual eliminators are pulled downwardly by their individual springs such as 31$, which are connected to the plate 32! which extends across the rear of the movable eliminator frame serving as an anchor for the springs. When the forward stroke begins and the accumulator carriage is lifted, the lower ends of the eliminato rs will contact the eliminator cams 393. Combs 322 and 323 are provided as shown to maintain the spaced alignment of the eliminators.

Each eliminator carries on its upper forward portion a roller 32d, and when the eliminators are inoperative, these rollers are positioned slightly above the rear projecting portion 325 of each of therack bars. Consequently, in adding operations the rack bars may slide underneath the. rollers and betweenthe eliminators without interference. But in a total operation when the eliminators are lowered, if any eliminator is not drawn into a zero recess 302 of its associated cam, the rear end 325 of the associated rack will pass under and lift. slightly on the roller to prevent any further downward: movement of the eliminator.

To the left of the accumulator representing the 1 highest denomination in the total there may be one or more accumulators in zero position, and their associated eliminators will enter the recesses 302m their cams, and. the rollers carried by such eliminators will drop down far enough to positively block anyrearwardmovement of these associated racks. Hence, the associated type wheels cannot rotate out of non-printing position even though they havebeen released-bythe key board, and they will thereforev not print zeros. the eliminators havebeen lowered by the total control lever, any that are able to be pulled down- When wardly into the camrecesses 3132 may dosoinasmu h a theslots 325 and SZl in the eliminators no t; such movement under the action of the individual springs 3 l 9 However, each eliminator is provided with a projection 328 which extends, as shown in Fig. 14, to the left from the eliminator with which it is integral over a shoulder 329 on the eliminator next to the right thereof. Consequently, if any eliminator be held partially raised by the high portion of its eliminator cam, every eliminator to the right thereof will likewise be held up by theeo-action between these projections 328 and the shoulders 339. Hence for example, if the fifth bank from the right contains a sum which should be printed in a total, its eliminator cam will not be in zero position, its eliminator will be held up-by the high portion of the cam, and every eliminator to the right will likewise be held up, and the type wheels to the right will print zeros or higher digits in accordance with the total then existing in the machine. Restoration of the total lever to normal position will in an obvious manner restore the eliminators to their inoperative position, which is shown in Fig. 2.

A spacing comb 332, shown in Fig. 2, is provided for spacing the accumulator sectors, and the comb 333 serves to space the ends of the carrier pawls and the lockingpawls. Another comb 334, shown in Fig. 2, spaces the type Wheels.

While one embodiment of the present invention is herein illustrated and described in considerable detail, it should be understood that the invention is capable of considerable modification without departing from the spirit and scope of the invention defined in the appended claim.

Having shown and described my invention, I claim:

In a calculating machine, a pair of parallel shafts. one above the other, type wheels on the upper shaft, accumulator driving gears on the lower shaft, numeral key-controlled means reciprocating between said shafts for driving the type wheels and said gears, sets of three pinion gears intermeshed on three adjacent shafts, one of each set being selectively engageable with the driving gears for addition, a second of each set being engageable with the driving gears for subtraction, and means co-acting with the third of each, set of gears in total-taking operations for preventing the printing of zeros to the left of the highest order digit in the total, said pinion gears being. arranged for reciprocation in the plane of their axes and in a direction perpendicular to their axe-s.

THOMAS O. MEHAN. 

